The Germany defender has repeatedly been linked with Manchester United and Liverpool in recent transfer windows - and now his former boss Jurgen Klopp is at Anfield.

But Watzke says Hummels' relationship with Dortmund is still strong.

He explained: "Everybody gets criticised but honestly, that massive criticism of the last days is unreasonably high in my opinion.

"Today I read of a problematic relation between Mats and us.

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STAR PLAYER: Dortmund captain Hummels

"But that’s definitely not true.

"Mats Hummels is a very important player for us.

"He is our captain. I have an excellent relationship with him.

"Sometimes he is not too easy, but that does not have to be a disadvantage.

"He is a very decent guy, and we will support him entirely.

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PALS: Klopp and Hummels last year

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SPEAKING OUT: Dortmund chief Watzke

"There is nothing more to say about it."

Hummels joined Dortmund from Bayern Munich, initially on loan, in 2008.

He has developed into one of the most revered centre-backs in world football, shining as Germany won the 2014 World Cup and playing a major role as Dortmund won the Bundesliga titles in 2011 and 2012 before reaching the 2013 Champions League final.

This season he has featured in 22 matches already as Dortmund have climbed to second in the Bundesliga and reached the top of their Europa League group.